The average temperature at 40,000 feet above sea level is -60 F.
56
A ball of glass will bounce higher than a ball made of rubber.
73
A cubic yard of air weighs about 2 pounds at sea level.
31
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
A single speck of dust is half way in size between a subatomic particle and the Earth.
15
One third of the electricity produced on earth is used to power electric light bulbs!
75
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75